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sync with latest libbpf (iovisor#2594)
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The following helpers are sync'ed into bcc and will
be available in linux 5.5.
  bpf_probe_read_kernel
  bpf_probe_read_kernel_str
  bpf_probe_read_user
  bpf_probe_read_user_str

Signed-off-by: Yonghong Song <[email protected]>
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yonghong-song authored Nov 13, 2019
1 parent a6f658d commit 992e482
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Showing 6 changed files with 139 additions and 43 deletions.
9 changes: 7 additions & 2 deletions docs/kernel-versions.md
Original file line number Diff line number Diff line change
Expand Up @@ -203,6 +203,10 @@ Helper | Kernel version | License | Commit |
`BPF_FUNC_perf_event_read_value()` | 4.15 | GPL | [`908432ca84fc`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=908432ca84fc229e906ba164219e9ad0fe56f755)
`BPF_FUNC_perf_prog_read_value()` | 4.15 | GPL | [`4bebdc7a85aa`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4bebdc7a85aa400c0222b5329861e4ad9252f1e5)
`BPF_FUNC_probe_read()` | 4.1 | GPL | [`2541517c32be`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2541517c32be2531e0da59dfd7efc1ce844644f5)
`BPF_FUNC_probe_read_kernel()` | 5.5 | GPL | [`6ae08ae3dea2`](https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=6ae08ae3dea2cfa03dd3665a3c8475c2d429ef47)
`BPF_FUNC_probe_read_kernel_str()` | 5.5 | GPL | [`6ae08ae3dea2`](https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=6ae08ae3dea2cfa03dd3665a3c8475c2d429ef47)
`BPF_FUNC_probe_read_user()` | 5.5 | GPL | [`6ae08ae3dea2`](https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=6ae08ae3dea2cfa03dd3665a3c8475c2d429ef47)
`BPF_FUNC_probe_read_user_str()` | 5.5 | GPL | [`6ae08ae3dea2`](https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=6ae08ae3dea2cfa03dd3665a3c8475c2d429ef47)
`BPF_FUNC_probe_read_str()` | 4.11 | GPL | [`a5e8c07059d0`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=a5e8c07059d0f0b31737408711d44794928ac218)
`BPF_FUNC_probe_write_user()` | 4.8 | GPL | [`96ae52279594`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=96ae52279594470622ff0585621a13e96b700600)
`BPF_FUNC_rc_keydown()` | 4.18 | GPL | [`f4364dcfc86d`](https://git.kernel.org/cgit/linux/kernel/git/bpf/bpf-next.git/commit/?id=f4364dcfc86df7c1ca47b256eaf6b6d0cdd0d936)
Expand Down Expand Up @@ -236,6 +240,7 @@ Helper | Kernel version | License | Commit |
`BPF_FUNC_skb_get_xfrm_state()` | 4.18 | | [`12bed760a78d`](https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id=12bed760a78da6e12ac8252fec64d019a9eac523)
`BPF_FUNC_skb_load_bytes()` | 4.5 | | [`05c74e5e53f6`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=05c74e5e53f6cb07502c3e6a820f33e2777b6605)
`BPF_FUNC_skb_load_bytes_relative()` | 4.18 | | [`4e1ec56cdc59`](https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id=4e1ec56cdc59746943b2acfab3c171b930187bbe)
`BPF_FUNC_skb_output()` | 5.5 | | [`a7658e1a4164`](https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=a7658e1a4164ce2b9eb4a11aadbba38586e93bd6)
`BPF_FUNC_skb_pull_data()` | 4.9 | | [`36bbef52c7eb`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=36bbef52c7eb646ed6247055a2acd3851e317857)
`BPF_FUNC_skb_set_tunnel_key()` | 4.3 | | [`d3aa45ce6b94`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d3aa45ce6b94c65b83971257317867db13e5f492)
`BPF_FUNC_skb_set_tunnel_opt()` | 4.6 | | [`14ca0751c96f`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=14ca0751c96f8d3d0f52e8ed3b3236f8b34d3460)
Expand Down Expand Up @@ -298,7 +303,7 @@ The list of program types and supported helper functions can be retrieved with:
|`BPF_PROG_TYPE_SK_SKB`|`BPF_FUNC_skb_store_bytes()` <br> `BPF_FUNC_skb_load_bytes()` <br> `BPF_FUNC_skb_pull_data()` <br> `BPF_FUNC_skb_change_tail()` <br> `BPF_FUNC_skb_change_head()` <br> `BPF_FUNC_get_socket_cookie()` <br> `BPF_FUNC_get_socket_uid()` <br> `BPF_FUNC_sk_redirect_map()` <br> `BPF_FUNC_sk_redirect_hash()` <br> `BPF_FUNC_sk_lookup_tcp()` <br> `BPF_FUNC_sk_lookup_udp()` <br> `BPF_FUNC_sk_release()` <br> `Base functions`|
|`BPF_PROG_TYPE_CGROUP_DEVICE`|`BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_get_current_uid_gid()` <br> `BPF_FUNC_trace_printk()`|
|`BPF_PROG_TYPE_SK_MSG`|`BPF_FUNC_msg_redirect_map()` <br> `BPF_FUNC_msg_redirect_hash()` <br> `BPF_FUNC_msg_apply_bytes()` <br> `BPF_FUNC_msg_cork_bytes()` <br> `BPF_FUNC_msg_pull_data()` <br> `BPF_FUNC_msg_push_data()` <br> `BPF_FUNC_msg_pop_data()` <br> `Base functions`|
|`BPF_PROG_TYPE_RAW_TRACEPOINT`|`BPF_FUNC_perf_event_output()` <br> `BPF_FUNC_get_stackid()` <br> `BPF_FUNC_get_stack()` <br> `Tracing functions`|
|`BPF_PROG_TYPE_RAW_TRACEPOINT`|`BPF_FUNC_perf_event_output()` <br> `BPF_FUNC_get_stackid()` <br> `BPF_FUNC_get_stack()` <br> `BPF_FUNC_skb_output()` <br> `Tracing functions`|
|`BPF_PROG_TYPE_CGROUP_SOCK_ADDR`|`BPF_FUNC_get_current_uid_gid()` <br> `BPF_FUNC_bind()` <br> `BPF_FUNC_get_socket_cookie()` <br> `Base functions`|
|`BPF_PROG_TYPE_LWT_SEG6LOCAL`|`BPF_FUNC_lwt_seg6_store_bytes()` <br> `BPF_FUNC_lwt_seg6_action()` <br> `BPF_FUNC_lwt_seg6_adjust_srh()` <br> `LWT functions`|
|`BPF_PROG_TYPE_LIRC_MODE2`|`BPF_FUNC_rc_repeat()` <br> `BPF_FUNC_rc_keydown()` <br> `BPF_FUNC_rc_pointer_rel()` <br> `BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_ktime_get_ns()` <br> `BPF_FUNC_tail_call()` <br> `BPF_FUNC_get_prandom_u32()` <br> `BPF_FUNC_trace_printk()`|
Expand All @@ -308,5 +313,5 @@ The list of program types and supported helper functions can be retrieved with:
|Function Group| Functions|
|------------------|-------|
|`Base functions`| `BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_map_peek_elem()` <br> `BPF_FUNC_map_pop_elem()` <br> `BPF_FUNC_map_push_elem()` <br> `BPF_FUNC_get_prandom_u32()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_get_numa_node_id()` <br> `BPF_FUNC_tail_call()` <br> `BPF_FUNC_ktime_get_ns()` <br> `BPF_FUNC_trace_printk()` <br> `BPF_FUNC_spin_lock()` <br> `BPF_FUNC_spin_unlock()` |
|`Tracing functions`|`BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_probe_read()` <br> `BPF_FUNC_ktime_get_ns()` <br> `BPF_FUNC_tail_call()` <br> `BPF_FUNC_get_current_pid_tgid()` <br> `BPF_FUNC_get_current_task()` <br> `BPF_FUNC_get_current_uid_gid()` <br> `BPF_FUNC_get_current_comm()` <br> `BPF_FUNC_trace_printk()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_get_numa_node_id()` <br> `BPF_FUNC_perf_event_read()` <br> `BPF_FUNC_probe_write_user()` <br> `BPF_FUNC_current_task_under_cgroup()` <br> `BPF_FUNC_get_prandom_u32()` <br> `BPF_FUNC_probe_read_str()` <br> `BPF_FUNC_get_current_cgroup_id()` <br> `BPF_FUNC_send_signal()`|
|`Tracing functions`|`BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_probe_read()` <br> `BPF_FUNC_ktime_get_ns()` <br> `BPF_FUNC_tail_call()` <br> `BPF_FUNC_get_current_pid_tgid()` <br> `BPF_FUNC_get_current_task()` <br> `BPF_FUNC_get_current_uid_gid()` <br> `BPF_FUNC_get_current_comm()` <br> `BPF_FUNC_trace_printk()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_get_numa_node_id()` <br> `BPF_FUNC_perf_event_read()` <br> `BPF_FUNC_probe_write_user()` <br> `BPF_FUNC_current_task_under_cgroup()` <br> `BPF_FUNC_get_prandom_u32()` <br> `BPF_FUNC_probe_read_str()` <br> `BPF_FUNC_get_current_cgroup_id()` <br> `BPF_FUNC_send_signal()` <br> `BPF_FUNC_probe_read_kernel()` <br> `BPF_FUNC_probe_read_kernel_str()` <br> `BPF_FUNC_probe_read_user()` <br> `BPF_FUNC_probe_read_user_str()`|
|`LWT functions`| `BPF_FUNC_skb_load_bytes()` <br> `BPF_FUNC_skb_pull_data()` <br> `BPF_FUNC_csum_diff()` <br> `BPF_FUNC_get_cgroup_classid()` <br> `BPF_FUNC_get_route_realm()` <br> `BPF_FUNC_get_hash_recalc()` <br> `BPF_FUNC_perf_event_output()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_skb_under_cgroup()`|
1 change: 1 addition & 0 deletions introspection/bps.c
Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,7 @@ static const char * const prog_type_strings[] = {
[BPF_PROG_TYPE_CGROUP_SYSCTL] = "cgroup_sysctl",
[BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE] = "raw_tracepoint_writable",
[BPF_PROG_TYPE_CGROUP_SOCKOPT] = "cgroup_sockopt",
[BPF_PROG_TYPE_TRACING] = "tracing",
};

static const char * const map_type_strings[] = {
Expand Down
150 changes: 110 additions & 40 deletions src/cc/compat/linux/virtual_bpf.h
Original file line number Diff line number Diff line change
Expand Up @@ -174,6 +174,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_CGROUP_SYSCTL,
BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
BPF_PROG_TYPE_CGROUP_SOCKOPT,
BPF_PROG_TYPE_TRACING,
};

enum bpf_attach_type {
Expand All @@ -200,6 +201,7 @@ enum bpf_attach_type {
BPF_CGROUP_UDP6_RECVMSG,
BPF_CGROUP_GETSOCKOPT,
BPF_CGROUP_SETSOCKOPT,
BPF_TRACE_RAW_TP,
__MAX_BPF_ATTACH_TYPE
};

Expand Down Expand Up @@ -421,6 +423,7 @@ union bpf_attr {
__u32 line_info_rec_size; /* userspace bpf_line_info size */
__aligned_u64 line_info; /* line info */
__u32 line_info_cnt; /* number of bpf_line_info records */
__u32 attach_btf_id; /* in-kernel BTF type id to attach to */
};

struct { /* anonymous struct used by BPF_OBJ_* commands */
Expand Down Expand Up @@ -561,10 +564,13 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_probe_read(void *dst, u32 size, const void *src)
* int bpf_probe_read(void *dst, u32 size, const void *unsafe_ptr)
* Description
* For tracing programs, safely attempt to read *size* bytes from
* address *src* and store the data in *dst*.
* kernel space address *unsafe_ptr* and store the data in *dst*.
*
* Generally, use bpf_probe_read_user() or bpf_probe_read_kernel()
* instead.
* Return
* 0 on success, or a negative error in case of failure.
*
Expand Down Expand Up @@ -1426,45 +1432,14 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
* int bpf_probe_read_str(void *dst, u32 size, const void *unsafe_ptr)
* Description
* Copy a NUL terminated string from an unsafe address
* *unsafe_ptr* to *dst*. The *size* should include the
* terminating NUL byte. In case the string length is smaller than
* *size*, the target is not padded with further NUL bytes. If the
* string length is larger than *size*, just *size*-1 bytes are
* copied and the last byte is set to NUL.
*
* On success, the length of the copied string is returned. This
* makes this helper useful in tracing programs for reading
* strings, and more importantly to get its length at runtime. See
* the following snippet:
*
* ::
*
* SEC("kprobe/sys_open")
* void bpf_sys_open(struct pt_regs *ctx)
* {
* char buf[PATHLEN]; // PATHLEN is defined to 256
* int res = bpf_probe_read_str(buf, sizeof(buf),
* ctx->di);
*
* // Consume buf, for example push it to
* // userspace via bpf_perf_event_output(); we
* // can use res (the string length) as event
* // size, after checking its boundaries.
* }
*
* In comparison, using **bpf_probe_read()** helper here instead
* to read the string would require to estimate the length at
* compile time, and would often result in copying more memory
* than necessary.
* Copy a NUL terminated string from an unsafe kernel address
* *unsafe_ptr* to *dst*. See bpf_probe_read_kernel_str() for
* more details.
*
* Another useful use case is when parsing individual process
* arguments or individual environment variables navigating
* *current*\ **->mm->arg_start** and *current*\
* **->mm->env_start**: using this helper and the return value,
* one can quickly iterate at the right offset of the memory area.
* Generally, use bpf_probe_read_user_str() or bpf_probe_read_kernel_str()
* instead.
* Return
* On success, the strictly positive length of the string,
* including the trailing NUL character. On error, a negative
Expand Down Expand Up @@ -2751,6 +2726,96 @@ union bpf_attr {
* **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
*
* **-EPROTONOSUPPORT** IP packet version is not 4 or 6
*
* int bpf_skb_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
* Description
* Write raw *data* blob into a special BPF perf event held by
* *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
* event must have the following attributes: **PERF_SAMPLE_RAW**
* as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
* **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
*
* The *flags* are used to indicate the index in *map* for which
* the value must be put, masked with **BPF_F_INDEX_MASK**.
* Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
* to indicate that the index of the current CPU core should be
* used.
*
* The value to write, of *size*, is passed through eBPF stack and
* pointed by *data*.
*
* *ctx* is a pointer to in-kernel struct sk_buff.
*
* This helper is similar to **bpf_perf_event_output**\ () but
* restricted to raw_tracepoint bpf programs.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_probe_read_user(void *dst, u32 size, const void *unsafe_ptr)
* Description
* Safely attempt to read *size* bytes from user space address
* *unsafe_ptr* and store the data in *dst*.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
* Description
* Safely attempt to read *size* bytes from kernel space address
* *unsafe_ptr* and store the data in *dst*.
* Return
* 0 on success, or a negative error in case of failure.
*
* int bpf_probe_read_user_str(void *dst, u32 size, const void *unsafe_ptr)
* Description
* Copy a NUL terminated string from an unsafe user address
* *unsafe_ptr* to *dst*. The *size* should include the
* terminating NUL byte. In case the string length is smaller than
* *size*, the target is not padded with further NUL bytes. If the
* string length is larger than *size*, just *size*-1 bytes are
* copied and the last byte is set to NUL.
*
* On success, the length of the copied string is returned. This
* makes this helper useful in tracing programs for reading
* strings, and more importantly to get its length at runtime. See
* the following snippet:
*
* ::
*
* SEC("kprobe/sys_open")
* void bpf_sys_open(struct pt_regs *ctx)
* {
* char buf[PATHLEN]; // PATHLEN is defined to 256
* int res = bpf_probe_read_user_str(buf, sizeof(buf),
* ctx->di);
*
* // Consume buf, for example push it to
* // userspace via bpf_perf_event_output(); we
* // can use res (the string length) as event
* // size, after checking its boundaries.
* }
*
* In comparison, using **bpf_probe_read_user()** helper here
* instead to read the string would require to estimate the length
* at compile time, and would often result in copying more memory
* than necessary.
*
* Another useful use case is when parsing individual process
* arguments or individual environment variables navigating
* *current*\ **->mm->arg_start** and *current*\
* **->mm->env_start**: using this helper and the return value,
* one can quickly iterate at the right offset of the memory area.
* Return
* On success, the strictly positive length of the string,
* including the trailing NUL character. On error, a negative
* value.
*
* int bpf_probe_read_kernel_str(void *dst, u32 size, const void *unsafe_ptr)
* Description
* Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr*
* to *dst*. Same semantics as with bpf_probe_read_user_str() apply.
* Return
* On success, the strictly positive length of the string, including
* the trailing NUL character. On error, a negative value.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
Expand Down Expand Up @@ -2863,7 +2928,12 @@ union bpf_attr {
FN(sk_storage_get), \
FN(sk_storage_delete), \
FN(send_signal), \
FN(tcp_gen_syncookie),
FN(tcp_gen_syncookie), \
FN(skb_output), \
FN(probe_read_user), \
FN(probe_read_kernel), \
FN(probe_read_user_str), \
FN(probe_read_kernel_str),

/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
Expand Down
15 changes: 15 additions & 0 deletions src/cc/export/helpers.h
Original file line number Diff line number Diff line change
Expand Up @@ -524,6 +524,21 @@ static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal;
static long long (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *ip,
int ip_len, void *tcp, int tcp_len) =
(void *) BPF_FUNC_tcp_gen_syncookie;
static int (*bpf_skb_output)(void *ctx, void *map, __u64 flags, void *data,
__u64 size) =
(void *)BPF_FUNC_skb_output;
static int (*bpf_probe_read_user)(void *dst, __u32 size,
const void *unsafe_ptr) =
(void *)BPF_FUNC_probe_read_user;
static int (*bpf_probe_read_kernel)(void *dst, __u32 size,
const void *unsafe_ptr) =
(void *)BPF_FUNC_probe_read_kernel;
static int (*bpf_probe_read_user_str)(void *dst, __u32 size,
const void *unsafe_ptr) =
(void *)BPF_FUNC_probe_read_user_str;
static int (*bpf_probe_read_kernel_str)(void *dst, __u32 size,
const void *unsafe_ptr) =
(void *)BPF_FUNC_probe_read_kernel_str;

/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions
Expand Down
5 changes: 5 additions & 0 deletions src/cc/libbpf.c
Original file line number Diff line number Diff line change
Expand Up @@ -208,6 +208,11 @@ static struct bpf_helper helpers[] = {
{"sk_storage_delete", "5.2"},
{"send_signal", "5.3"},
{"tcp_gen_syncookie", "5.3"},
{"skb_output", "5.5"},
{"probe_read_user", "5.5"},
{"probe_read_kernel", "5.5"},
{"probe_read_user_str", "5.5"},
{"probe_read_kernel_str", "5.5"},
};

static uint64_t ptr_to_u64(void *ptr)
Expand Down

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